diff options
| author | Eric Dumazet <edumazet@google.com> | 2025-06-15 10:51:49 -0700 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2025-06-27 11:04:24 +0100 |
| commit | b010c36371ca2d99057722d3e16f064085c131ac (patch) | |
| tree | 531dcb543659c7b18c0c158fb11b77e968cbec98 | |
| parent | 458b8e2d6a62fb621692377d02c82f45073a05fd (diff) | |
| download | linux-b010c36371ca2d99057722d3e16f064085c131ac.tar.gz linux-b010c36371ca2d99057722d3e16f064085c131ac.tar.bz2 linux-b010c36371ca2d99057722d3e16f064085c131ac.zip | |
net_sched: sch_sfq: annotate data-races around q->perturb_period
[ Upstream commit a17ef9e6c2c1cf0fc6cd6ca6a9ce525c67d1da7f ]
sfq_perturbation() reads q->perturb_period locklessly.
Add annotations to fix potential issues.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://lore.kernel.org/r/20240430180015.3111398-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
[ Harshit: Backport to 5.10.y, conflicts resolved due to missing commit:
d636fc5dd692 ("net: sched: add rcu annotations around qdisc->qdisc_sleeping")
in 5.10.y ]
Signed-off-by: Harshit Mogalapalli <harshit.m.mogalapalli@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | net/sched/sch_sfq.c | 13 |
1 files changed, 9 insertions, 4 deletions
diff --git a/net/sched/sch_sfq.c b/net/sched/sch_sfq.c index 6b65c5efb378..aceb7502d523 100644 --- a/net/sched/sch_sfq.c +++ b/net/sched/sch_sfq.c @@ -611,6 +611,7 @@ static void sfq_perturbation(struct timer_list *t) struct Qdisc *sch = q->sch; spinlock_t *root_lock = qdisc_lock(qdisc_root_sleeping(sch)); siphash_key_t nkey; + int period; get_random_bytes(&nkey, sizeof(nkey)); spin_lock(root_lock); @@ -619,8 +620,12 @@ static void sfq_perturbation(struct timer_list *t) sfq_rehash(sch); spin_unlock(root_lock); - if (q->perturb_period) - mod_timer(&q->perturb_timer, jiffies + q->perturb_period); + /* q->perturb_period can change under us from + * sfq_change() and sfq_destroy(). + */ + period = READ_ONCE(q->perturb_period); + if (period) + mod_timer(&q->perturb_timer, jiffies + period); } static int sfq_change(struct Qdisc *sch, struct nlattr *opt) @@ -662,7 +667,7 @@ static int sfq_change(struct Qdisc *sch, struct nlattr *opt) q->quantum = ctl->quantum; q->scaled_quantum = SFQ_ALLOT_SIZE(q->quantum); } - q->perturb_period = ctl->perturb_period * HZ; + WRITE_ONCE(q->perturb_period, ctl->perturb_period * HZ); if (ctl->flows) q->maxflows = min_t(u32, ctl->flows, SFQ_MAX_FLOWS); if (ctl->divisor) { @@ -724,7 +729,7 @@ static void sfq_destroy(struct Qdisc *sch) struct sfq_sched_data *q = qdisc_priv(sch); tcf_block_put(q->block); - q->perturb_period = 0; + WRITE_ONCE(q->perturb_period, 0); del_timer_sync(&q->perturb_timer); sfq_free(q->ht); sfq_free(q->slots); |